Rotatable fenders

ABSTRACT

A fender, primarily for marine use, comprises a tyred wheel rotatably mounted in a support structure and clutch means operable to prevent rotation of the wheel. The clutch means comprises a pair of opposed, externally frusto-conical clutch elements which are movable in unison into and out of engagement with respective complementary internally frusto-conical surfaces formed in the hub of the wheel. The clutch means includes a device for automatically taking up the wear on the clutch faces.

United States Patent 1 Duncan et al.

[ 1 Apr. 3, 1973 [54] ROTATABLE FENDERS [75] Inventors: John Duncan,Giles; Graham Arthur Nigel Hart, Aylesbury, both of England COMPRESSEDAIR 2,045,593 6/1936 Frankland ..188/72.8 X

- 2,091,586 8/1937 Glacy ..l88/72.8 X

FOREIGN PATENTS OR APPLICATIONS 701,606 12/1953 Great Britain ..1 14/220764,276 12/1956 I Great Britain ..1 14/220 Primary ExaminerMiltonBuchler Assistant Examiner-Gr'egory W. OConnor Attorney-Ernest A.Greenside [57] ABSTRACT A fender, primarily for marine use, comprises atyred wheel rotatably mounted in a support structure and clutch meansoperable to prevent rotation of the wheel. The clutch means comprises apair of opposed, externally frusto-conical clutch elements which aremovable in unison into and out of engagement with respectivecomplementary internally frusto-conical surfaces formed in the hub ofthe wheel. The clutch means includes a device for automatically takingup the wear on the clutch faces.

6 Claims, 2 Drawing Figures PATENTEDAPRS i975 SHEET 2 OF 2 ROTATABLEFENDERS This invention relates to rotatable fenders intended primarilybut not exclusively for tugs and like vessels which are used to maneuverother vessels by pushing them.

According to this invention, there is provided a rotatable fendercomprising a tired wheel mounted for rotation about a fixed axis andhaving a hub which rotates with the wheel, and a clutch including twointernal annular frustoconical clutch surfaces which are provided by thehub and are centered on said axis and which face in axially oppositedirections, two clutch elements having external annular frusto-conicalclutch surfaces respectively co-operating with said internal clutchsurfaces which elements are fixed against rotation about said axis butare guided for axial movement, and clutch operating means for moving theclutch elements towards and away from each other in unison for operatingthe clutch. Preferably the clutch operating means is actuated by amotor.

According to a preferred feature of the invention, the clutch operatingmeans comprises two nuts respectively connected to the two clutchelements which nuts have opposite handed threads, and a shaft havingrespective threaded portions in screw engagement with the nuts, saidmotor being connected to rotate the shaft selectively in eitherdirection.

According to another preferred feature of the invention, control meansfor controlling the operation of the clutch is adapted to engage theclutch by running the motor until the clutch elements are in full tightengagement with the internal clutch surfaces on the hub and the motorstalls. In this case the motor is preferably a fluid operated rotarymotor so as not to be adversely affected by operating under stallingconditions.

Conveniently the fender may include means for automatically compensatingfor wear on the clutch surfaces.

According to a preferred feature of the invention, the automaticwear-compensating means comprises means adapted, on initiation ofoperator of operation of the motor to disengage the clutch, to back offthe clutch elements from a position of full, tight engagement with theinternal clutch surfaces for a first predetermined interval of time and,on initiation of operation of themotor to engage the clutch, to move theclutch elements for a second predetermined interval of time from thisfully disengaged position in a sense to engage the clutch, said secondtime interval being longer than said first time interval.

One embodiment of the invention will now be described by way of examplewith reference to the accompanying drawings in which:

FIG. 1 shows, half in axial section, a pneumatic bow fender according tothe invention, and

FIG. 2 is an inverted plan of the base support member of the fender.

Referring to the drawings, the fender is mounted in the bow of a tug andincludes a pneumatic tired wheel mounted for rotation about a verticalaxis 1 l and arranged so that the tire projects forwardly beyond thestem 12 of the tug.

The wheel has a hub 13 within which is secured, as by welding, afabricated convergent-divergent element 14 providing two internalaxially outwardly facing,

frusto-conical clutch faces 15, 16. Also welded to the hub are twobearings rings 17 which are disposed at opposite ends of the hub. Eachof these rings has an internal bearing surface 18 and an axiallyoutwardly facing bearing surface 19 which are respectively engaged bycomplementary plain surfaces 20, 21 of a journal ring 22 and a thrustring 23. The upper rings 22 and 23 are secured to a fixed upper supportmember 24 and the lower rings are secured to a generally similar basesupport member 25. The bearings are protected against the ingress ofwater by seals 26.

The hub has two inflation valves 27 which communicate with the interiorof the tire through passages in the upper bearing ring 17.

Each of the two support members 24, 25 carries a set of four guide pins30 which project axially into the hub and a clutch member 31 having anexternal frusto-conical surface 32 is supported for axial slidingmovement on these four guide pins, the member having having bushes 33 inwhich the guide pins engage. The surfaces 32 of the clutch members arerespectively complementary to the faces 15, 16 of element 14 andintermediate clutch linings 34 are provided which are secured to themembers 31.

Each of the clutch members 31 has a nut 35 secured within it, and thescrew threads of the two nuts are of opposite hand to each other. Acentral shaft 36 has opposite-handed screw portions respectively engagedwithin the two screws so as to support the members 31 and is journalledin the two support members 24, 25. The upper end of the shaft 36 isdriven by the output shaft of a reduction gear mechanism 37 mounted onthe deck 39 of the tug, and the input shaft of mechanism 37 is driven bya reversible compressed air motor 40.

The wheel and the two support members are disposed between the deck anda generally horizontal support plate 43 spaced below the deck. To securethe fender in position the bottom flange 44 of support member 25 isprovided with an outer ring of threaded holes 45, and an inner ring ofeight larger threaded holes 46 which are on the same pitch circle as theguide pins 30. Bolts 47, 48 extend through drillings in the plate 43into the holes 45, 46 and hold the support member 25 rigidly againstplate 43. The top flange 50 of support member 24 has an outer pitchcircle along which screw-threaded holes alternate with shallow recesses51, and an inner pitch circle in which screwthreaded holes alternatewith shallow recesses 52. The deck has threaded holes aligned with therecesses and plain holes aligned with the screwed holes in flange 50,and threaded studs 53, 54 having hexagonal sockets in their upper endscarry lock nuts 55, 56 and project into the recesses 51 and 52. Thesestuds are arranged to press the entire fender assembly downward againstsupport plate 43, and bolts 57, 58 are then screwed into the threadedholes in the flange 50 to hold the flange and the deck against relativevertical movement and, with the studs, resist the tendency of thesupport plate to rotate whel the wheel is rotating and the clutch isbeing engaged to stop the wheel.

When the tug is pushing another vessel the wheel is held stationary, theclutch being fully engaged. When it is desired to move the point ofapplication of the push, the clutch is disengaged and the helm put over,and the tug will then move sideways, the wheel rolling along the side ofthe other vessel, until the fresh point of application is reached whenthe clutch is engaged to stop the wheel. Thus the need to back the tugoff is avoided. In addition the pneumatic tire of the wheel spreads theload applied to the other vessel.

The clutch is applied by driving motor 40 in one direction so thatclutch members 31 are moved towards each other by virtue of theengagement of their respective nuts 35 with the screw threads on theshaft so that the members engage the respective internal clutch faces15, 16. It is of course essential for the wheel to become locked to themembers 31 and for this reason the members 31 and element 14 constitutea clutch rather than a brake. To disengage the clutch, the motor isreversed.

In order to provide for automatic adjustment to compensate for wear onthe clutch linings, a timing mechanism 59 is incorporated in thecontrols of the motor such that when the clutch is to be disengagedcompressed air is supplied to the motor for a predetermined interval oftime, and when the clutch is next engaged, compressed air is supplied tothe motor for a predetermined longer time interval. The motor thus tendsalways to move the clutch members further in the engaging than in thedisengaging direction, and is arranged always to reach a stalling point,indicative of full engagement of the clutch, at or before the expiry ofthe time set for operation of the motor to engage the clutch.

We claim:

1. A fender comprising a tired wheel mounted for rotation about avertical axis and having a hub which rotates with the wheel about saidaxis, a clutch mechanism having a first pair of annular frustoconicalrelatively immovable clutch surfaces provided by the hub and rotatablein unison therewith about said axis, said clutch mechanism having asecond pair of annular frusto-conical clutch surfaces fixed againstrotation about said axis but mounted for axial movement toward and awayfrom one another for respectively engaging and disengaging said firstpair of surfaces, and means for so moving said second pair of surfacesrelative to said first pair of surfaces. .7

2. A fender according to claim 1, wherein said tired wheel is adaptedfor predetermined positioning about said axis upon disengagement of saidsecond pair of surfaces from said first pair of surfaces and uponattainment of a predetermined position in its range of movement aboutsaid axis of said tired wheel, said means is operated to engage saidclutch surfaces.

3. A fender according to claim 1, mounted to a tug between its upperdeck and a generally horizontal support plate, spaced below the deck.

4. A fender according to claim 3, wherein the fender has upper and lowersupport members respectively fixed to the deck and said support plate,each of said support members carrying guide means which project axiallyinto the hub, each of said second pair of surfaces being supported foraxial sliding movement on said guide means.

5. A fender as claimed in claim 1, wherein the lastnamed means comprisesa pair of nuts operatively connected to the second pair of clutchsurfaces of the clutch mechanism, said nuts having opjposite handedthreads, a shaft having respective threa ed portions in screw engagementwith the nuts, and a motor connected to rotate the shaft selectively ineither direction. 6. A fender as claimed in claim 5, comprising timingmeans effective to operate said motor for a first period of time in onedirection and for a second period of time longer than the first periodin an opposite direction.

UNTIED STATES PATENT oTT QETEFIIQATE @F QQFTRECTEQN Patent 3,724,413Dated April 3 1973 Inventor S) DUNCAN y JOHN ET AL It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

On the cover sheet {73] 0 "Heisbands Shipyards Limited should readHusband's Shipyards Limited, o

Signed and sealed this 25th day of December 1973.

( A Attest:

EDWARD M.a FLETCHERMR RENE D. TEGTMEYER Acting Commissioner of PatentsAttesting Officer USCOMM'DC 60376-P69 U,Sv GOVERNMENT HUNTING OFFICEX959 0-366-334.

F QRM PO-l 050 (10-69)

1. A fender comprising a tired wheel mounted for rotation about avertical axis and having a hub which rotates with the wheel about saidaxis, a clutch mechanism having a first pair of annular frustoconicalrelatively immovable clutch surfaces provided by the hub and rotatablein unison therewith about said axis, said clutch mechanism having asecond pair of annular frusto-conical clutch surfaces fixed againstrotation about said axis but mounted for axial movement toward and awayfrom one another for respectively engaging and disengaging said firstpair of surfaces, and means for so moving said second pair of surfacesrelative to said first pair of surfaces.
 2. A fender according to claim1, wherein said tired wheel is adapted for predetermined positioningabout said axis upon disengagement of said second pair of surfaces fromsaid first pair of surfaces and upon attainment of a predeterminedposition in its range of movement about said axis of said tired wheel,said means is operated to engage said clutch surfaces.
 3. A fenderaccording to claim 1, mounted to a tug between its upper deck and agenerally horizontal support plate, spaced below the deck.
 4. A fenderaccording to claim 3, wherein the fender has upper and lower supportmembers respectively fixed to the deck and said support plate, each ofsaid support members carrying guide means which project axially into thehub, each of said second pair of surfaces being supported for axialsliding movement on said guide means.
 5. A fender as claimed in claim 1,wherein the last-named means comprises a pair of nuts operativelyconnected to the second pair of clutch surfaces of the clutch mechanism,said nuts having opposite handed threads, a shaft having respectivethreaded portions in screw engagement with the nuts, and a motorconnected to rotate the shaft selectively in either direction.
 6. Afender as claimed in claim 5, comprising timing means effective tooperate said motor for a first period of time in one direction and for asecond period of time longer than the first period in an oppositedirection.